I have looked this question up. We are supposed to choose the option that contains the transitional word present in the sentence.
Answer:
The transitional word in the sentence is:
a. However
Step-by-step explanation:
As their name suggests, transitional words are words used to connect sentences or paragraphs. They help the author of a text to go from one idea to the next smoothly. Transitional words establish a relationship between the paragraphs such as cause and consequence, opposition, conclusion, sequence in time, etc. Examples of transitional words are: therefore, however, while, finally, thus, etc.
In the sentence we are analyzing here, the transitional word is "however". That means this sentence expresses an idea that opposes another idea expressed previously, in another sentence or even in another paragraph.